'68 Malibu ignition switch problem

Working on a '68 Malibu with a 350 Crate motor (HEI Distributor) and what I believe is the original ignition switch.

When I stick the key in the ignition switch, both the ignition and the accessory circuits go hot with 12v without even turning the key. (i.e. with the key in the center position, as long as the key is in the ignition, both circuits are hot). I can see this voltage both at the fuse block, and in other places like at the 12v wire that goes to the HEI distributor.

Looks like an obviously bad ignition switch to me, do I need to replace both the switch and the lock cyl, or just the switch? Other ideas?

Thanks
Jon

PS: Really glad I found this problem as the car is new to me, and looks to me like a potential fire hazard if I were to leave the key hanging in the ignition (example: the electric choke would be hot all the time).